The present invention relates to an electrical terminal strip for potential multiplication. The electrical terminal strip includes an insulating terminal housing having a plurality of openings arranged in a row. At least one terminal contact row is located in the insulating terminal housing. The terminal contact row has a plurality of contact connections disposed side by side in the row direction. Each contact connection includes a conductor terminal element having a receiving space located therein. Each receiving space is in registration with a respective terminal housing opening, and extends in the direction approximately perpendicular to a direction of the row. The receiving spaces receive respective protective conductors inserted from an outside of the terminal housing and through the respective terminal housing openings. The contact connection further includes a conductor protecting element inserted into the respective receiving space. The protective conductor is clamped between the conductor protecting element and the conductor terminal element to contact the conductor protecting element and the conductor terminal element. At least one connector pin protrudes out from the terminal housing and is electrically connected to a contact connection.
German Offenlegungsschrift (application published without examination) No. 42 28 025 discloses such a terminal strip for connection to printed circuit boards. The insulating terminal housing according to this publication contains a single terminal contact row that comprises a number of contact connections lined up one next to the other.
A soldered connector pin, which protrudes out from the terminal housing, is associated with each contact connection.
A conductor, which is inserted from the outside into the terminal housing, can be electrically connected to any of the contact connections. In doing so, the conductor is inserted into a receiving space of a respective conductor terminal element, which functions as a tension sleeve, and clamped firmly between a clip-like conductor protecting element and the conductor terminal element.
The conductor protecting element is likewise disposed in the receiving space of the conductor terminal element and is connected in one piece to the soldered connector pin. The firmly clamped conductor is therefore connected to the associated soldered connector pin in an electrically conductive manner.
If a potential multiplication is desired, as is required in many cases such as with protective conductors, the relevant soldered connector pins have to be connected to one another independently of the printed circuit. To accomplish this, typically a connection bar is provided, which extends in the direction of the row of contact connections, and which is slipped onto the soldered connector pins from the outside of the terminal housing to engage the soldered connector pins with electrically contacting clamping pressure.
A disadvantage associated with this connection bar is that the connection bar must be subsequently placed on the terminal housing as a separate element, and consequently, requires additional assembly of the terminal strip.
Further, since the connection bar is slipped onto the soldered connector pins from the outside of the housing, and remains on the outside of the housing even in an assembled condition, the connection bar is not protected against external influences. The connection bar can therefore be easily mechanically damaged.
In addition, an outer region of the connection bar can inadvertently come into contact with, for example, a current-carrying conductor and as a result, can cause a short circuit or other damage to elements of the printed circuit board. Thus, potential multiplication using the aforementioned connection bar may be unsafe.
A Further disadvantage of the known connection bar is that the connection bar needs a complicated geometrical shape to produce a sufficient, electrically contacting clamping pressure between the connection bar and the soldered connector pins. Consequently, the production cost of the terminal strip is high.
German Patent No. 42 07 402 discloses a terminal strip for electrically connecting actuators, sensors, initiators, or the like to printed circuit boards of an SPC (=stored program control) plug-in unit. This known terminal strip contains a plurality of terminal contact rows. For potential multiplication, the contact connections of a terminal contact row can be connected using a covered, internal bridge located inside the terminal housing.